Drill-steel centralizer



G. M. NELL July 1, 1930.

DRILL STEEL CENTRALI ZER Filed March 12, 1929 Patented July 1, 1930 I S=AT GUSTAVE M. NELI, F DETROIT, MICHIGAN, ASSlGNOR T0 CHICAGO COMPANY, OF NEW YORK, N. A. CORPORATION OF NEW 7 FICE' PNEUMATIC TOOL JERSEY DRILL-STEEL CENTRALIZER Application filed March 12, 1929. Serial no. 346,283.

This invention relates to'rock drilling apparatus with particular reference to guiding devices for the drill steels, frequently referred to as centralizers;

One objectof the invention is to provide improved means for supporting and guiding drill steels so as to spot holes accurately, to prevent crawling, and to permit starting holes on an inclined or rough rock surface. Another object isto permit the guide or centralizer proper to be moved out of the way when no longer needed without the use of tools and without disconnecting it from the rest of the apparatus. Other objects will be apparent from the detailed description which follows.

1 In order to illustrate the invention one concrete embodiment thereof is shown in the accon'ipanying drawings, in winch:

ward end of a shell mounting with the centralizer apparatus attached thereto and indicating the manner of use of the same;

.Fig. 2 is a top plan View of the apparatus shown in Fig. 1 with the drilling machine omitted but showing a broken away portion of the drill steel; and

Fig. 3 is a right end elevational View of the apparatus shown in Figs. land 2.

The invention takes the form of an attachment adapted to be applied to the conventional type of shell mounting 4 which has guide grooves (Fig. 3) to receive cooperating wing projections or flanges of a drilling machine such as A which is fed to and retracted from the work by the usual feed screw 4 (Fig. The attachment includes a base or face plate 5 secured to the forward end of shell 4 by the conventional side bolts 4 and byone or more additional bolts 6, if necessary or desirable. Base or plate 5 may be, or may take the place of, the usual end plate and may provide a bearing 5 (Fig. 2) for feed screw 4 as indicated. Plate 5 has a reduced projecting portion 5 in line with feed screw 4 and with the axis of the shell mounting to which is secured in any suitable manner as by pin or rivet 7 a tubular or hollow extension 8 which hasa tapered forward end 8 of any F 1 is a side elevational view of the fordesired shape in cross section; in the present instance it is shown as square.

Mounted uponthe tapered forward end 8 is a guide member 9 havinga tapered socket 9 conforming to the shape of extension end 8*. Member 9 has axially spaced guide arms 9? and 9which are generally semcircular in shape as indicated in Fig. 3 and arranged to interengageopposite sides of the drill steel a which is supported in drilling machine A. The space between the guide armsf9 'and 9 permits the insertion and removal of the drill steel from the guide member by disposing these parts transverse to one another rather than in the' parallel-a xial planes in which member 9 guides the steel as shown.

Resilient means are provided for retaining gui'demember 9 in place on extension end 3 whilepermitting its removal therefrom for engagement or disengagement with drill steel a or for replacement in a difierent position of angular adjustment. Such means may take the form of a coil spring 10 housed within the shell extension. Pins 8 and 9 may be provided in extension 8 and guide membert) respectively for securingthe endsof spring '10 thereto. With this construction, extension end 8 is'required to be slotted as indicated at 8? to receive pin 9 when member 9 is applied thereto and the number ofslots, together withthe configuration of the exten- -tion end 8 determines thenumber of permissible positions of angular adjustment of guide -member 9. In the present instance slots 8, being in a horizontal plane only permit but two positions of member 9 on extension 8. The full line position shown in Fig. 1 is the operative one in which member 9 serves as a guide fordrill steel a while the reverse position, indicated in broken lines in the same figure, is the inoperativeposition The use of the apparatus will be quite clear from the previous description. Withv the parts in the position shown. in all of the figures of the drawing, steel a is guided by. arms 9* and 9 for starting a hole. After the hole is started and the guiding of the forward portion of the drill is no longer necessary, the 013- erator grasps member 9 and pulls it in the directionuof the arrow (Fig. 1) against the tenoutline in Fig. 1. To arrange member 9 to guide-the drill steel, the above operations are reversed.

While the invention has been herein clescribed in what is now considered to be a preferred form, it is to be understood that the invention is not limited to the specific .details thereofbut covers all changes, modifications and adaptations within the scope of the appended claims.

I .claim as my invention:

1. The combination with a shell mounting for a drilling machine of a guide "for the drill steel arranged to be supported on said mounting in. a plurality of positions, and resilient means for holding said guide on said mounting in each of said positions.

2. A shell mounting for rock drills having an extension, a guide for the drill steel arranged to fit on the end of said extension in a pluralityof positions of angular adjustment, and means maintaining a resilient connection between said guide and said mounting during changes of position.

3. A shell mounting for rock drills hav ing an extension provided with a tapered end, aguide for the drill steel having a socket arranged tofit said tapered end in a plurality of positions of angular adjustment, and means preventing separation of said guide from said extension. but permitting changes in the position of said guide thereon.

4. A shell mounting for rock drills having an extension, a guide for the drill steel movable axially on and ofi said support, and resilient means for holding said guide in place. r

5. A shell mounting for drilling machines having a hollow extension, a drill steel guide movable axially on and off said support, and

resilient means within said support for holding said guide in place. I 6; A shell mounting for drilling machines having a hollow extension, a guide or the drill steel of the machine movable axially on and oil said support, and a coil spring within said extension secured to said guide for holding. the latter in place but permitting 'adjustment of its position upon said exten- '7. A shell mounting for drilling machines having an extension, a guide for the drill steel of the machine, cooperating means on said extension and. on said guide providing for mounting the latter on the former in a plurality of positions of angular adjustment, and means continuously operable to hold said guide in place but permitting changes in the position of the latter.

8. A shell mounting for drilling machines having an extension provided with a tapered polygonal end, a guide member for the drill steel of the machine having a socket to fit the end of said extension, said member hav ing spaced guide projections for engaging the opposite sides of the drill steel, and a flexible connection between said extension and said member for yieldingly holding the latter in place on the former but permitting its 

